I could be wrong but it seems PLAN follows the pattern of "building ships for available engines" instead of the other way around. 052C only became a possibilty after GT25000 were acquired. Now that its indigenious version QC260 has turned out, PLAN can re-open the 052C production line again after all these years of pause. As to the even larger destroyer that carries more vertical launched missiles (& tackles everybody's imagination for years), we just have to pray for the progress on the LM2500 class gas turbine: QC185.
The same story goes for 054 series. The number of Pilstick disels they bought pretty much determines the number of ships that would eventually roll out. However, the upgraded 054(B?) is likely to have its displacement increased for more equipments; or higher speed to be part of the future carrier group; or even lower length-wideth ratio to improve the seaworthiness. I would say only a couple of gas turbines could make all those things happen, to be more specific, two QC185s with nearly 18MW power each would be idea for a 5000-ton size frigate (& four for Destroyers on par with USN Arleigh Burke).
I won't bet my money on a new design before at least another batch of 054A make their appearances at HD/HP, 2012 perhaps.:coffee: